Abstract:The problem of zonal enrichment of thorium and uranium is dealt with in this paper through an investigation of a certain deposit. Although characterized by close paragenetic association, thorium and uranium in this deposit show relative zonal enrichment corresponding to the zoning of altered rocks: three gradational mineralization zones or thorium enrichment zone thorium- uranium zone→uranium enrichment zone can be recognized correspondant with three alteration zones or red zone →green zone→light-colored zone. Frequency distribution of Th/U indicates that the samples can be assigned to two parent-populations of logarithmic normal distribution which represent two connected yet different geologic-geochemical processes dominated respectively by uranium and by thorium. The regression equations fitting Th to U are: Th = 1.801 U0.787; Th = 2.397 U1.254. Regression analyses of uranium and thorium versus oxides imply that correlation between two variables approximates to the function y = axb. Thorium and uranium have identical correlated variables and symbols, yet the differences in absolute values of the power b of the correlated equations suggest that diverse extent of' enrichment of thorium and uranium is reflected in the variation in Th/U ratios. Although these two elements tend to be concentrated simultaneously, one element was probably getting more dominant as the processes of enrichment advanced, that accounts for the zonal enrichment of thorium and uranium. Investigations show that, as two correlated yet different geologic- geochemical processes, the thorium and uranium mineralizations must have had a direct connection with the evolution of altered rocks. The general tendency of petrochemical evolution of altered rocks resulted in the zonal enrichment of thorium and uranium, and the uneven evolution of altered rocks decided the locations of thorium and uranium mineralizations.
文章编号：
中图分类号：
文献标志码：
引用文本：
戴杰敏, 陶代廉.1984.某矿床钍、铀分带性的研究[J].矿床地质,3(3):76~84.1984.A Study Of Thorium-Uranium Zoning In A Certain Deposit[J].Mineral Deposits3(3):76~84
图/表
